The present invention relates generally to chucks for use with drills or with electric or pneumatic power drivers. More particularly, the present invention relates to a chuck of the keyless type which may be tightened or loosened by hand.
Both hand and electrical or pneumatic tool drivers are well known. Although twist drills are the most common tools on such drivers, the tools may also comprise screw drivers, nut drivers, burrs, mounted grinding stones, and other cutting or abrading tools. Since the tool shank may be of varying diameter or of polygonal cross section, the device is usually provided with a chuck that is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore or any other suitable means.
A variety of chuck types have been developed that are actuated by relative rotation between a chuck body and an annular nut. In a typical oblique jawed chuck, for example, a body member includes three passageways disposed approximately 120xc2x0 apart from each other. The passageways are configured so that their center lines meet at a point along the chuck axis forward of the chuck body. Three jaws are constrained by and movable in the passageways to grip a cylindrical tool shank disposed approximately along the chuck center axis. The nut rotates about the chuck""s center and engages threads on the jaws so that rotation of the nut moves the jaws in either direction in the passageways. The body and nut are configured so that rotation of the nut in one direction (the closing direction) with respect to the body forces the jaws into gripping relationship with the tool shank, while rotation in the opposite direction (the opening direction) releases the gripping relationship. Such a chuck may be keyless if it is rotated by hand. Examples of such chucks are disclosed in U.S. Pat. Nos. 5,125,673 and 5,193,824, commonly assigned to the present assignee and the entire disclosure of each of which is incorporated by reference herein. Various configurations of keyless chucks are known in the art and are desirable for a variety of applications.
Keyless chucks actuated by relative rotation between a nut and a chuck body include means to control the rotational position of the nut and the body. For example, a first sleeve may be provided in communication with the nut while a second sleeve, which is independent of the first sleeve, may be attached to the body. Thus, a user may rotate the first sleeve with one hand while gripping the second sleeve with the other hand, thereby holding the body still. Alternatively, in some devices in which only a single sleeve is provided, a user may grip the single sleeve and actuate the tool driver to rotate the spindle, thereby rotating the chuck body with respect to the sleeve. In addition, a mechanism may be located in a driver to lock the spindle of the driver when the driver is not actuated, thus enabling use of a single sleeve chuck.
The present invention recognizes and addresses the foregoing considerations, and others, of prior art constructions and methods.
Accordingly, it is an object of the present invention to provide an improved chuck.
It is a further object of the present invention to provide an improved drill.
It is a still further object of the present invention to provide a chuck having an improved mechanism for loosening and tightening the chuck.
These and other objects are achieved by a chuck for use with a manual or powered driver having a housing and a rotatable drive shaft extending therefrom. The chuck includes a generally cylindrical body member having a nose section and a tail section. The tail section is configured to mate with the drive shaft so that the body rotates with the drive shaft. The nose section has an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. Each of a plurality of jaws is slidably positioned in one of the annularly disposed passageways. Each of the jaws has a jaw face formed on one side thereof and threads formed on the opposite side thereof. A nut is rotatably mounted on the body in engagement with the threads on the jaws so that rotation of the nut moves the jaws axially within the passageways. A locking member is, in a first axial position, rotatable with respect to the driver housing. In a second axial position, it operatively engages the housing and the nut so that the locking member is rotationally held to the housing and to the nut so that the nut is rotationally held to the housing. The locking member is axially reciprocal between the first axial position and the second axial position.
In another preferred embodiment, a chuck includes a generally cylindrical body member having a nose section and a tail section. The tail section is configured to mate with the drive shaft so that the body rotates with the drive shaft. The nose section has an axial bore formed therein and a plurality of angularly disposed passageways formed therethrough and intersecting the axial bore. Each of a plurality of jaws is slidably positioned in one of the angularly disposed passageways. Each jaw has a jaw face formed on one side thereof and threads formed on the opposite side thereof. A nut is rotatably mounted on the body in engagement with the threads on the jaws so that rotation of the nut moves the jaws axially within the passageways. The chuck also includes an axially reciprocal sleeve and a clutch mechanism disposed operatively between the body and the nut. The sleeve is rotationally held to, and axially movable with respect to, the clutch mechanism in at least one axial position of the sleeve. The clutch mechanism and the nut include respective engaging surfaces disposed so that the clutch mechanism and the nut are rotationally held to each other when engaged by a rotational force applied at the engaging surfaces by at least one of the clutch mechanism and the nut and so that the clutch mechanism is urged axially away from the nut upon application of the rotational force. A biasina mechanism is in operative communication with the clutch mechanism and opposes axial movement of the clutch mechanism away from the nut. The biasing mechanism is configured with the clutch mechanism to resist disengagement of the engaging surfaces until the rotational force exceeds a predetermined level.
Other objects, features and aspects of the present invention are discussed in greater detail below.